Steel quart cans vanished in the early 1960s, if not before. I bought engine oil in a 10-quart steel can in 1973. Those disappeared soon after that.
The cardboard-steel hybrid cans that replaced all-steel lasted until the early to mid-1980s. They did not require the clumsy, tricky, push-in spout. Their main fault was susceptibility to being dropped, which crushed the cardboard, resulting in leaks.
I doubt typical modern plastic quarts are significantly, if any, more space-efficient than round quarts. What they gain with their roughly rectangular main cross-section, they lose with the tapered upper part. Cases of plastic quarts are smaller and lighter mainly because they contain only half as much oil as the old 24-quart boxes did.
The cardboard-steel hybrid cans that replaced all-steel lasted until the early to mid-1980s. They did not require the clumsy, tricky, push-in spout. Their main fault was susceptibility to being dropped, which crushed the cardboard, resulting in leaks.
I doubt typical modern plastic quarts are significantly, if any, more space-efficient than round quarts. What they gain with their roughly rectangular main cross-section, they lose with the tapered upper part. Cases of plastic quarts are smaller and lighter mainly because they contain only half as much oil as the old 24-quart boxes did.